A team of researchers at the Queen Mary University of London, with help from Nokia, has developed a prototype cellphone that charges using sound waves in the atmosphere. The secret is super-sensitive zinc oxide nanowires, which convert those sound vibrations into electrical currents. This means, hopefully in the nearer future, cellphones can be charged—sans cable—merely by the sound of your voice during a phone call, background traffic or a hectic coffee shop. No more fighting over the seldom outlet.
Siri, Charge My Phone